RC Brushless spindle

[njhussey]

The problem is with 12V and 270kV you'll only have max 3240 RPM which is from a practical point of view too low for Ali, Plastic and MDF, well technically it's not but the feeds will be very slow. With 24V yes you will have to think about cooling the motor (a couple of 12V PC Radiator fans in series mounted round the motor would do it) if you're doing long runs but you get better speed. I ran my spindle off 2 HP Server PSU's wired together to give 24V (and over 1000 Watts) and it was fine, but I didn't do many long runs and didn't use it in anger as I have a 2.2kW water cooled spindle which is fantastic! If I made one again I'd put water cooling in the bearing holder body as they do start to run hot after a while.

One suggestion is to make the spindle unit (don't over engineer it) and have the motor drive it by belt, if you make an adjustable motor mounting plate (or different ones you can swap over) then you can use different kV motors depending on what you want to cut, so larger lower kV motor for cutting Ali, MDF and Plastic and high kV smaller motor for engraving glass etc...